[dannyfarwin]

I purchased one of the generic overload relays, a Mars 21310 for a replacement of the original WR7X8 on the unit. Unfortunately, the unit has 5 connections with four being used. Two apparently for Common, and Start (black wires and white wires), but there are two connections that appear to be thermostat hookups. The replacement only has three connections, start run and common. I am assuming that one of the thermostat connections goes to start, and one to the common, but want to make sure before I blow things up.

The WR7X8 is hooked as follows:
One white wire on P1 (thermostat?)
Two black wires on P2
One white wire on P3 (thermostat?)
Two white wires on P4
P5 not used

[Gene]

The new relay should come with the installation instructions. Unfortunately we are not able to find any technical information on line for such old model and for this relay as well.

Gene.

[dannyfarwin]

Yes, unfortunately, the instructions only indicated 3 connections, not 4.

[Gene]

Try to talk to relay manufacturer.

Gene.